Rationale and study design for a randomised controlled trial to reduce sedentary time in adults at risk of type 2 diabetes mellitus: project stand (Sedentary Time ANd diabetes)

A reduction in sedentary time is targeted using theory driven group structured education. The STAND programme is subject to piloting and process evaluation in line with the MRC framework for complex interventions. Participants are encouraged to self-monitor and self-regulate their behaviour. The intervention is being assessed in a randomised controlled trial with 12 month follow up. Inclusion criteria are a) aged 18-40 years with a BMI in the obese range; b) 18-40 years with a BMI in the overweight range plus an additional risk factor for T2DM. Participants are randomised to the intervention (n = 89) or control (n = 89) arm. The primary outcome is a reduction in sedentary behaviour at 12 months as measured by an accelerometer (count < 100/min). Secondary outcomes include physical activity, sitting/lying time using the ActivPAL posture monitor, fasting and 2 h oral glucose tolerance test, lipids, inflammatory biomarkers, body weight, waist circumference, blood pressure, illness perceptions, and efficacy beliefs for behaviour change.This is the first UK trial to address sedentary behaviour change in a population of younger adults at risk of T2DM. The results will provide a platform for the development of a range of future multidisciplinary interventions in this rapidly expanding high-risk population.Current controlled trials ISRCTN08434554, MRC project 91409.There has been a dramatic increase in the incidence of Type 2 Diabetes Mellitus (T2DM). Until recently T2DM was considered a disease of older adults, however, this condition is now diagnosed in children and young adults and between 1998 and 2005 there was an eightfold increase in the prevalence of T2DM in young people in the UK [1]. Younger adults with T2DM are more likely to be obese, have a strong family history of T2DM, lead a sedentary lifestyle, be of black or minority ethnic (BME) origin, and come from less affluent socio-economic groups [2-4]. At the time of diagnosis, one in five young people with T2DM hav